


Durability

by Pomander



Category: Undertale (Video Game)
Genre: Booty Calls, Butterscotch Dinosaur Pussy, Clothed Sex, Copulating Companions, F/M, Foreign Films, Friends With Benefits, Mentions of alcohol/alcoholism, Past Sanster, Probably pre-amalgamate, Rough Sex, Vague descriptions of hentai, fuck buddies, happy tears, pre-game, unprotected sex
Language: English
Status: In-Progress
Published: 2016-11-29
Updated: 2016-12-03
Packaged: 2018-09-02 23:55:29
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,876
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8688541
Author URL: https://archiveofourown.org/users/Pomander/pseuds/Pomander
Summary: Alphys and Sans become close friends, bonding over animated pornography and their combined loneliness.





	1. Hint: It wasn't a joke.

**Author's Note:**

> This one's gonna be a bit shorter, probably only 3 or 4 chapters. It might get a *little* sad, but it won't be a complete downer, and will get plenty smutty, fear not!

"You ever fool around with anyone in here?" he asked her, once.

The tiny screwdriver slipped from her hand and rolled along the desk. She heard it hit the floor as she turned in her chair to face him. "W-what do you mean?"

He sat on the edge of the cluttered table opposite her, swinging one foot back and forth. _He said he was here to help this time_ , but she had been too wrapped up in her delicate work to notice he had stopped, and was just there to watch. _Again_.

"I mean here at the lab."

She felt heat rise to her face. "No? W-w-why would I ever- w-wait, h-have you?"

He grinned. "Maybe."

"What?! When?? With WHO???? Not, not recently, right?"

"My boss," he said simply. His foot kept swinging.

 _The old royal scientist_. Sans had given her little snippets of information about the mysterious person who previously held her position, but never enough to form a complete picture of him. _This_ was certainly new.

"In the lab?"

"Yep. How about you?"

"Th-that's really indecent, Sans. I w- _work_ here."

"You also _live_ here, which is why I asked. I mean, where else would you go to hook up with s- oh wait, their place. Never mind."

Alphys bit her lip and looked away, feeling a blush spread across her face. "No, I um, h-haven't even been with anyone since before I became the r-royal scientist," She admitted. Not that it was even Sans's business. But it also wasn't likely that he would go around telling people about her love life. Sans was good at keeping secrets, which was part of why she let him hang around.

She was also just kind of lonely.

"Damn. So like, almost a year ago, then."

She nodded. It had actually been over two years since her last 'intimate encounter', but she wasn't going to correct him. "Yes. Well, I've been a little b-busy."

Sans leaned back, halting his swinging leg. "Sounds like you're overdue, doesn't it? Maybe we could hook up sometime."

All of her breath left her in a single loud wheeze. "I-I-I-I'm s-sorry?!"

He shrugged. "Just an idea, it's cool if you don't want to. Hell, maybe we could just watch some of that freaky anime porn together and call it a night."

"H-hentai," she corrected him, "it's c-called hentai. "

"I guess you'd know more about it than me," he said, shrugging.

She sputtered, scooting back in her chair. "I-I-I-"

"Heh, sorry. For real though, if you're not interested, it's fine. If you ever are, lemme know." He shot her a wink as he slid himself down from the edge of the table, and waving at her lazily with one hand, bid her farewell and walked away. Alphys slumped back against her chair, listening to the receding sound of his muffled, dragging footsteps, which stopped about halfway down the stairs. He never used the actual doors to the laboratory, preferring to just mysteriously appear or disappear.

 _He likes messing with me_ , she thought, her face burning. _He likes messing with everyone_.

She picked up her tools and set back to work, just barely focused on what she was doing.

_He's got some motive to turn this into a joke._

 

* * *

 

Over a week passed, and she heard nothing from him. Surprisingly, this had probably been the longest she'd gone without seeing him since he had started showing up at the lab. He had made a point of showing up at least once a week to bother her, sometimes actually helping her out. Most of the time, he just got in her business, or practiced one of his standup routines on her while she was trying to concentrate. Sometimes he showed up drunk, and tried to hide it. He probably had no idea how keen her sense of smell was. She rubbed her thumbs over the buttons on her phone, hesitating. She could send him a message and wait who knew how long for a response, or...

Without thinking, she hit the 'call' button. _Shoot_. Her hands shook as she slowly brought the phone up to her tympanum, counting the ringing on the other end. Three rings, four, and a click.

"Hey," she heard, followed by a long beep.

She sighed and hung up. There would be no sense leaving a message in his voicemail. Even if he bothered to check it, what would she say? _'Hey, Sans, are you feeling frisky? Because I've been-'_

A drum kick and the deep sound of a tuba rang out from her phone's speakers, jostling her from her thoughts, and she shrieked, almost dropping the device in her startled panic. Sans must have gotten a hold of her phone when she wasn't looking, and changed his ringtone. She hit the 'answer' button, and slowly brought the phone back up.

"H-hello?" she said, her voice shaking almost as much as her hands.

"Hey," said Sans, in the same deep breathy tone he set his voicemail greeting with, "What's up?"

"I um. I haven't s-s-seen you in a while," she said, "are you okay?"

"Ah, yeah," he replied easily. Alphys heard the crunching of snow on the other end, and wind crackling against the speaker. "Thought I may have overstepped things. Wanted to give you some space. Sorry 'bout that."

"Oh. N-no, you're f-f-f-fine! I figured you were just um, m-messing with me."

Near silence on the other end, save for the continued crunching of snow. She felt her stomach drop.

"Um, I'm not m-mad or anything, if you were! It's the kind of thing I'm-I'm used to. Heh."

If she listened closely, she could almost make out the sound of his breathing. Maybe it was the wind again.

" _Was_ it just a joke?" she asked timidly.

"Not really." He coughed. "I mean maybe. Ugh, I don't know. 'm sorry."

"Oh." She took a deep breath "Well, even if it was... I wouldn't mind you c-coming over... t-t-to watch a normal movie or something! Or if you really wanted, I could lend you some of my uh... my collection."

"Hm. Tempting."

"And I mean, if you're not too busy this weekend," _Oh no, what are you doing??? He just said it was a joke!!! Well, he basically said-_ "Uhm, I'm not, either. Not really."

"Yeah?"

"Y-yeah."

"How about I drop by later tonight?"

She looked around at her messy room. "S-sure! Like, maybe Nine-thirty?"

"Heh. See ya then."

And that was how Dr. Alphys, Royal Scientist and head of the Hotland Labs, made her first-ever booty call.


	2. Hint: there will be no subtitles.

Alphys realized for the first time that she really needed a couch or something. In the meantime, she and Sans utilized the simplest home-theater setup:

Sitting on the edge of her bed, with her laptop on a side-table in front of them.

She clenched the hem of her pajama shirt nervously. Sans offered her one of the sodas he'd brought with, and she graciously accepted, while he scrolled through the entirety of porn she'd collected on her computer. It was taking a while.

She took a moment to glance around at the remainder of her messy living quarters that she'd not had a chance to address before he arrived. He'd shown up on time, she hadn't been counting on that. (And he knocked, making use of the front entrance to the lab for the first time since he'd begun coming over.) He didn't seem to mind the clutter, and she supposed it almost always looked that way when she was working and he showed up. But _this-_

"How about this one?" Sans asked, pointing to an obscure title. " _Takomanko 3: Ravished and Ready Maid_. Sounds promising."

"O-oh, that one. Umm i-it's uhhh..."

"Does it have tentacles?"

"Well, yes, technically."

"Then it's perfect."

She took a huge swig of soda and held it in her mouth, unsure of whether she should tell him what was to come. He scooted back onto the bed beside her, and they watched. Silently. Because what can you say to your friend when one of the raunchiest pieces of anime porn that's made its way to the Underground is playing on your laptop, without subtitles, and your mouth is full of soda?

_You can't say anything, you just wait for the plot to pick up and the action to begin._

Alphys readied herself for forty total minutes of animated hell.

"Hey, can you understand any of what's happening?" Sans asked?

"B-bits and pieces," she admitted, "But I can't explain it without ruining the ending."

"There's a plot?"

"Y-yeah. Um, do you want me to skip ahead to the action scenes?"

"Nah, I'm good. I'll watch and see where this goes. I like the panty-shots."

"Oh, there are plenty more of those ahead."

Twenty six in ten minutes, actually. She and Sans kept count, out loud. Alphys also took the opportunity to point out a few continuity errors in the animation, that she had picked up from repeated watching.

"Holy shit her entire arm is gone!" Sans burst into laughter as Alphys paused the footage at one of the few frames for which, yes, the animators had forgotten to include Fumiko-chan's arm.

"Yep! Oh, don't worry, though, it comes back in three... two..." She unpaused the footage, "One! There it is!"

"Oh thank god, I was worried she'd have to hold that mega feather duster with only one arm!"

"Well, she COULD use her mouth," Alphys joked, demonstrating with her half-empty bottle of soda while she drank, hands-free.

"Or other orifices," Sans suggested, choosing to wiggle his brow bones instead of demonstrating directly.

Alphys just about died from soda inhalation. Sans patted her back as she coughed and sputtered, laughing and trying desperately to regain her breath.

"O-oh, here's where it starts to get good!" She pointed to the screen, where Fumiko's panties had just been removed by some unseen force.

"Woah," Sans whispered, his hand stilling on Alphys's back.

Their laughter died down as the action onscreen picked up, and erotic noises filled the air around them. Alphys distracted herself with the remainder of her drink, while Sans pulled away, sitting himself back down next to her. There was nothing she could say in regards to the scene before them that wouldn't make things awkward. Maybe Sans could pull it off, but not her.

She _wished_ he would say something. She glanced over at him quickly, without turning her head, wondering how he was reacting to the busty-anime-babe getting skewered with tentacles for their personal entertainment.

He looked... just as uncomfortable as she felt, his expression tight and cheekbones dusted with color. She caught his eyelights flicking over to her just before he looked away, and figured she probably looked about the same.

"Um."

His hand brushed against the side of her thigh, and she squeezed her legs together, reflexively.

"Sorry," he muttered, pulling his hand away.

"N-no, you're fine," she assured him. She made a deliberate effort to relax her legs, spreading them open just slightly. She looked over to Sans, and watched his gaze travel slowly from her lap, up to her face. She bit her lip. Fumiko-chan was nearing her first of eight climaxes. Alphys let her own gaze drop to Sans's hands, clenched in her sheets.

"You sure?" he asked quietly.

"I'm- j-just go for it, whatever you were doing. I'll let you know if I don't like it."

"Okay."

He scooted in closer to her, and brought one hand to rest in her lap, rubbing lazy circles into her thigh while they watched Fumiko get reamed. He traced his middle finger along the hem of her pajama shorts, and the low, pulsing ache of her arousal grew stronger. She was new to this situation, unsure whether it was more polite to keep her eyes trained on the screen, or on the person touching her. Surely the worst option was to keep glancing back and forth.

"C-can I touch you?" she ventured, turning to him. She met his heavy, lurid gaze for the briefest of moments before her eyes dropped to focus on his cheekbones, the curve of his jaw, anywhere else.

"Sure," he replied, lowly. His posture shifted, his body more accessible, more open to her touch. The motion of his hand on her thigh slowed, but did not cease.

She froze, her hand stuck midair, unsure of its place in this situation. _He's touching my thigh, do I go for his? Or is that uncreative? Should I rub his back? That's not very erotic, though!_ Sans turned his attention back to the computer screen, graciously ignoring her moment of panicked indecision. She steeled herself and placed her hand swiftly but gently on his hip, ready to pull away at the first sign of discomfort.

Instead, he relaxed a little, turning back to her with a flushed face and a lopsided smile. "You move fast," he teased. Relieved, she smiled back and allowed the tip of her tongue to peak out between her lips as she rubbed her palm firmly over the top of his hip bone. He let out a tiny puff of air and turned, shifting his weight to the hand he had previously rested on her thigh. He brought his other hand over instead, and slipped his fingers just under the hem of her shorts. She cast her eyes down to watch them disappear under the fabric, sliding toward her, inching closer to her nethers at a snail's pace. She pressed her thumb into the joint between his femur and his hip, and he shuddered, swearing under his breath.

The sounds of flesh meeting flesh, wet and slapping and writhing, filled the air around them, interspersed with high-pitched cries of pleasure. Sans turned back to the screen momentarily, his eyes wide. Alphys followed his gaze, much less surprised than sans to find that Fumiko now had sprouted her own set of tentacles, and was wreaking havoc with them.

"Heh. That's pretty hot," he mumbled.

"It's... yeah." She chuckled, averting her gaze from both him and the screen, embarrassed.

"Hey, Al?" he asked, quietly, "Do you really wanna do this?"

"Yes," she squeaked, oh boy, did she ever. "P-please?"

"K." He turned to face her and pushed his hand completely under her shorts, resting his fingers up against her slit, dragging the tips down the slick fabric of her panties.

"Ah!" she gasped, craning her head back. His cool, hard fingers rubbed back and forth, skating over her slit, pausing over her entrance. He pushed in, just a little, wetting the tips of his fingers and soaking her panties even more.

He leaned over her. "What do you want me to do?" he asked quietly.

"Um. I-I- isn't it uh, obvious?"

"Tell me."

"F-fu-"

"Hmm?"

"Fffffffuck me?"

" _How?_ "

"Ho-however you w-w-want?" she faltered, craning her head to look at him. "I didn't think this through," she admitted.

He looked apologetic, "I mean uh, how do you wanna do this? With clothes on? Without?" He moved his hand away from her entrance to rest on the inside of her thigh. "Should I use my mouth on you? Or something else?"

"Oh! I um, I didn't even think I _could_ leave my clothes on. C-can we do that?"

"Sure."

"Whew, okay! As for the rest... whatever feels good to you, I guess. I don't know much about how you work? I mean, your b-body."  
  
"I'll show you, don't worry. Lie on your back for me?"

She scooped her tail under and between her legs to lie back on the bed watching him. He straddled her tail, situating himself in front of her, then pulled the front of his shorts down with one hand, and closed his eyes. Blue light coalesced over his pelvis to form a short, thick member with a fat, slightly flared head. He opened his eyes again and met Alphys's stare with a grin.

"You ready?" he asked, bringing the head of his dick to her entrance.

"Y-yeah," she whispered, her knees and breath shaking.

"Cool. One more thing, just so you know: your clothes are gonna get real dirty, real fast. Mine too."

She laughed. "Okay."

He smiled and spread her open, pushing himself in.

"Oh- _oh_ my god," she breathed. Somewhere off to her side, Fumiko voiced a similar sentiment. She was wet enough that it didn't hurt, but Sans was kind of a tight fit. It took several slow, shallow thrusts to get her loose enough that he could fit in to the hilt. Once he was in all the way, he reached forward and gripped her waist, holding himself steady. She could feel him throbbing against her.

"Still good?" he asked. Alphys nodded. "Good." He began moving with slow, shallow thrusts that made her gasp and whimper. "Heh, you're really cute, you know that?" he whispered.

" _P-please_ don't start with me, I- ah! I'm enjoying this, I don't want to start thinking about how I l-look."

His fingers gripped the hem of her shirt. "Okay, okay, no skin off my back."

Alphys snickered, and he drove in deep. "Yesss," she moaned, her back arching. She wrapped her legs around his hips, squeezing him a little. Her hands reached for his.

"H-holy shit," he mumbled. She tightened her walls around him and he groaned, leaning down over her as the steady rhythm he'd been building faltered. "Mmn."

His face was close enough that she could lean up and kiss him. Was that a faux pas? Kissing your friend while they were trying to concentrate on having sex with you? She wasn't going to be the one to ask. He panted above her, grinning wildly. The zipper on his hoodie made a little 'clink' with every thrust into her, as it dangled.

"Want me to go a bit faster?" he asked.

"I-I mean if you're offering."

"I am."

"Th-then go ahead?"

"Okay."

Sans pulled his hands from hers, sliding his fingers down her body, over her hips, until they rested on her thighs, where he squeezed, hard. He kept his eyes on hers as he pulled himself halfway out of her. "Ready?" he asked.

"Yes?" she also asked.

He jammed himself back in with enough force that it made her yelp in surprise, and by that time, then pulled back slammed in again. And again. His hips pushed him into her, swiftly and relentlessly, jostling her. She reached out to either side of her and gripped the sheets in an effort to still her body while he moved.

A futile effort.

"Ohhh, fuck!" she gasped.

Sans's brows were furrowed together in an expression of concentration, but his smile was wide. His still expression fell in sharp contrast with the thundering she was feeling against the walls of her pussy, the pounding of his hips against her thighs. She squeezed him a bit more, and felt his fingertips digging into her in response.

She felt her climax building like the approach of a freight train, much more sudden and severe than she was used to. She cried out in a high-pitched whimper, and the force of Sans's ministrations shook her voice, so the sound came out in a series of squeaks.

"Heh. You doin' okay there, Al?" he rasped.

"I'm- oh, I think i'm going to- hnn. P-please don't stop!"

"I won't."

She bit her lip as her climax rose, and kept coming. Tears formed in the corners of her eyes. Every inward thrust sent a shockwave through her, and by the time she felt Sans slowing down, she was struggling to catch her breath, taking oxygen back in little by little in heavy gasps.

He slipped himself out of her, and she felt him shaking between her legs as he let out a long, strained, breathy groan. Little by little, warm, sticky splatters of cum coated the inside of her thigh.

They stayed as they were, for a moment, basking in the afterglow, the warm feeling of closeness settling over them.

On the screen next to them, the credits were beginning to roll.

"That was pretty great," she whispered, "I mean, jeez, I didn't expect you to go full out like that, but I'm glad you did."

Sans chuckled. "Sorry about that, got a little too... _into_ it. Do you have any thing I can clean you up with?" he asked, gently, pulling back.

"Yeah, I um, It's around here somewhere, I've got a shirt-" She leaned up and reached over to the side of the bed, rooting around in a small pile of clothes. She pulled a wrinkled pink shirt out of the pile, and brought it up to her lap. Sans smirked and took it from her, and wiped her leg clean gently.

"What's that look for?" she asked.

"Nothin', we've got a lot in common, is all. You're soaked, by the way."

He was right. Not only were her panties a lost cause, there was still cum on her shorts, and her pajama shirt was wrinkled and warped where Sans had gripped it.

"Ugh. I've gotta do laundry, anyway." She looked him over. His shirt and hoodie weren't any dirtier than usual, but his shorts were almost as soaked as hers on the front. "Um, do you wanna stay for a bit? I think I've got a pair of sweatpants that'll fit you. Or something." She slid off the bed and resumed searching through the pile of clothes.

He shrugged. "Sure. Got any snacks?"

"Downstairs. Go, help yourself while I throw these in the wash." She handed him a pair of sweatpants in exchange for his shorts, and sauntered off, with Sans's dirty clothes under one arm, and fresh clothes for her in the other. She kept her washing machine on the same floor as her bed, knowing herself well enough that if it was on another floor, her laundry would never get done. She turned to make sure Sans was out of the room, then stripped down and changed, and tossed their things in together. When she turned back toward her bed, he was watching her, with a large bowl of popcorn in his arms.

They both flushed in embarrassment.

"What um, what do you want to do now?" he asked her.

She gave him a lopsided smile and a shrug in response. "We could watch a movie?"

"Sounds good. Actually I've got one I think you might like. Wait here just a sec."

He set the bowl of popcorn on the bed and vanished, leaving Alphys alone. She sat down on the bed and brought the bowl into her own lap, too relaxed and worn out to be startled when he reappeared directly in front of her, proudly displaying a DVD.

"I think you'll like this one, Alphys."

"Go ahead and put it in," she offered, gesturing to her laptop.

He gave her a wink before turning to insert the disk into her computer, then turned and flopped down onto the bed next to her. "Thanks for lettin' me come over," he muttered, as the disc began to play.

"Thanks for offering," she replied. They used each other as pillows, and the opening credits began.

The movie played out in Italian, with no subtitles.

Both of them drifted to sleep long before it was over.


End file.
